The subject matter disclosed herein relates to elevator systems. More specifically, the subject matter relates to sway mitigation of ropes of elevator systems.
During periods of, for example, high velocity winds, buildings tend to sway laterally. As a building sways, lateral motion of the building typically translates into lateral motion of ropes and cables of elevator systems installed in the building. The lateral motion of the ropes and cables can result in noise, wear, and/or damage to elevator system equipment and/or the building.
Typically, one of several approaches are utilized to mitigate rope sway issues. The first uses mechanical means to restrain the ropes to limit rope sway. Such devices include cab followers and swing arms as described, for example, in U.S. Pat. No. 5,947,232. Such mechanical devices are potentially effective to limit rope sway, but are costly and take up space in the hoistway.
A second approach typically involves limiting elevator car operations during periods of building sway. This involves a sensor added to the elevator system which detects building sway. When sway exceeds a preset limit, a set of alternate control instructions are placed on the elevator system to, for example, reduce operating speed of the elevator and/or to restrict parking access of the elevator car at floors where rope sway is likely to occur.